On 11/18/2012 02:55 PM, Andrew Lunn wrote:
This is not sufficient. In fact it makes no difference at all. The problem is not with the structure, but with the allocation of memory used to contain the structure.pstapriv->pallocated_stainfo_buf = _malloc(sizeof(struct sta_info) * NUM_STA + 4); if (pstapriv->pallocated_stainfo_buf == NULL) return _FAIL; pstapriv->pstainfo_buf = pstapriv->pallocated_stainfo_buf + 4 - ((addr_t)(pstapriv->pallocated_stainfo_buf) & 3); kmalloc() guarantees that its alignment is correct for any type of structure. Thus all this code above is redundant in Linux, but maybe needed in some other OS. Worse still, this code actually breaks the alignment. kmalloc() gave out something which was 64 bit aligned. But by adding 4 and then masking off the lower 2 bits, it destroys the 64 bit alignment and makes it only 32bit aligned. Removing the _malloc() wrapper, fixing the GFP_ATOMIC, and leaving the allocater to worry about alignment will be one of the steps to getting out of staging.
As you surmised, the original driver was meant for several Windows systems as well as Linux.
This driver will not make it out of staging until it supports the mac80211 stack. Work to accomplish this has started by modifying the rtl8192se code to work with the USB interface. I will make certain that the alignment issues are fixed there.
Thanks for the lesson, Larry -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
